Add LangGraph agent system: client.ts

langgraph-agents/client.ts

@@ -0,0 +1,137 @@
+/**
+ * ForensiX AI — TypeScript SSE Client for Next.js
+ * 
+ * Usage in Next.js pages:
+ *   import { streamInvestigation, resumeInvestigation } from '@/lib/forensic-client';
+ */
+
+const API_BASE = process.env.NEXT_PUBLIC_AGENT_API_URL || 'http://localhost:8000';
+
+export interface AgentEvent {
+  type: 'thread_id' | 'agent_update' | 'interrupt' | 'complete' | 'error';
+  thread_id?: string;
+  agent?: string;
+  completed_agents?: string[];
+  new_findings?: number;
+  new_correlations?: number;
+  risk_score?: number;
+  risk_level?: string;
+  findings?: any[];
+  correlations?: any[];
+  explanation?: string;
+  investigative_leads?: string[];
+  risk_factors?: Record<string, number>;
+  errors?: string[];
+  data?: any;
+  error?: string;
+}
+
+export interface InvestigateInput {
+  case_id: string;
+  report_text?: string;
+  evidence?: { timestamp: string; source: string; eventType: string; details: string; lat?: number; lon?: number }[];
+  cctv_frames?: string[];
+  toxicology_data?: { substance: string; level: string }[];
+  thread_id?: string;
+}
+
+/**
+ * Stream a full investigation through the 8-agent LangGraph pipeline.
+ * Returns an AbortController to cancel.
+ */
+export function streamInvestigation(
+  input: InvestigateInput,
+  onEvent: (event: AgentEvent) => void,
+  onError?: (error: Error) => void,
+): AbortController {
+  const controller = new AbortController();
+
+  fetch(`${API_BASE}/api/investigate/stream`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify(input),
+    signal: controller.signal,
+  })
+    .then(async (res) => {
+      if (!res.ok) {
+        const text = await res.text();
+        throw new Error(`Server error ${res.status}: ${text}`);
+      }
+      const reader = res.body!.getReader();
+      const decoder = new TextDecoder();
+      let buffer = '';
+
+      while (true) {
+        const { done, value } = await reader.read();
+        if (done) break;
+        buffer += decoder.decode(value, { stream: true });
+        const lines = buffer.split('\n\n');
+        buffer = lines.pop() ?? '';
+
+        for (const line of lines) {
+          if (line.startsWith('data: ')) {
+            try {
+              const event: AgentEvent = JSON.parse(line.slice(6));
+              onEvent(event);
+            } catch (e) {
+              console.warn('Failed to parse SSE event:', line);
+            }
+          }
+        }
+      }
+    })
+    .catch((err) => {
+      if (err.name !== 'AbortError') {
+        onError?.(err);
+      }
+    });
+
+  return controller;
+}
+
+/**
+ * Resume an investigation after human-in-the-loop interrupt.
+ */
+export async function resumeInvestigation(
+  threadId: string,
+  response: string,
+  onEvent: (event: AgentEvent) => void,
+): Promise<void> {
+  const res = await fetch(`${API_BASE}/api/investigate/resume`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ thread_id: threadId, response }),
+  });
+
+  if (!res.ok) throw new Error(`Resume failed: ${res.status}`);
+
+  const reader = res.body!.getReader();
+  const decoder = new TextDecoder();
+  let buffer = '';
+
+  while (true) {
+    const { done, value } = await reader.read();
+    if (done) break;
+    buffer += decoder.decode(value, { stream: true });
+    const lines = buffer.split('\n\n');
+    buffer = lines.pop() ?? '';
+    for (const line of lines) {
+      if (line.startsWith('data: ')) {
+        try { onEvent(JSON.parse(line.slice(6))); } catch {}
+      }
+    }
+  }
+}
+
+/**
+ * Get current state of an investigation thread.
+ */
+export async function getInvestigationState(threadId: string) {
+  const res = await fetch(`${API_BASE}/api/investigate/state`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ thread_id: threadId }),
+  });
+  if (!res.ok) throw new Error(`State fetch failed: ${res.status}`);
+  return await res.json();
+}